Download Novell IPX

Novell IPX
Semester 3, Chapter 7
Allan Johnson
Novell IPX Overview

Novell IPX is a proprietary suite of protocols
that includes the following:



A connectionless layer 3 protocol that does not
require an acknowledgement for each packet.
A layer 3 hierarchical addressing scheme with an
80 bit (10 byte) number that specifies the
network and node.
Why is it important to your CCNA?


Novell’s NOS, called NetWare, is the most popular
client/server application for connecting PCs to the
network.
It is implemented in more than 5 million networks
connecting more than 50 million clients.
The Novell IPX Protocol Suite
Novell Protocols and their corresponding OSI layer.
Application
Presentation
SAP
NCP
NetWare
Shell
Session
Transport
Network
SPX
IPX
Novell RIP
The Novell IPX Protocol Suite
Protocols discussed in detail are in Red.
Application
Presentation
SAP
NCP
NetWare
Shell
Session
Transport
Network
SPX
IPX
Novell RIP
Protocol Descriptions

SAP


IPX


facilitates the exchange of routing information and chooses
the best path based on hops and ticks.
NCP


Internet Packet Exchange provides layer 3 connectionless
addressing (network + node)
Novell RIP


Service Advertising Protocol advertises network services in
an SAP packet (includes GNS)
NetWare Core Protocol provides client-to-server connections
and applications (like GroupWise)
SPX

Sequenced Packet Exchange (like TCP) provides layer 4
connection-oriented services
IPX Addressing

The IPX address contains two parts:
The network number assigned by the network
administrator and...
 the node number which is usually the MAC address
of the device (no subnets!).
The network address is 32
bits (like an IP) that is
expressed in hexadecimal
format.
Notice in the graphic only 16
bits are shown. The leading
bits are zeros. The full
network address is 00004A1d.



A Brief Encapsulation History




The evolution of IEEE specs for Ethernet was
too slow for Novell.
So Novell came out with NetWare versions
based on what they thought IEEE’s Ethernet
frame would look like.
When IEEE came out with the final 802.3
frame format, it included the Logical Link
Control sublayer of the Data-Link Layer.
This made Novell’s NetWare versions
incompatible. So Novell came out with newer
versions.
A Brief Encapsulation History




Needless to say, all this confusion causes
headaches for the network administrator
trying to set the correct encapsulation on an
Ethernet interface.
To make things more complicated, Cisco has
its own names for the various Novell and
IEEE Ethernet formats.
On the next slide, these frame formats and
their corresponding names are listed.
Memorize them! You’ll be asked to show you
know these encapsulations on the CCNA
exam.
Multiple Novell Encapsulations
Novell Name
Novell Version
Cisco Name
Ethernet_802.3 3.11 or earlier
novell-ether
Ethernet_802.2 3.12 or later
sap
compatible with
Ethernet_II
TCP/IP
compatible with
Ethernet_SNAP
TCP/IP and AppleTalk
arpa
snap
When configuring a router’s Ethernet interface, you
need to enter the “Cisco name” above for the correct
encapsulation type.
Novell RIP

Novell RIP is a distance-vector routing protocol that
uses two metrics: hop count and ticks (1/18th of a
second), which is different than the tick of a
processor.




A CPU’s tick is one clock cycle. A 100MHz clock has
100million ticks per second. techweb
Novell RIP will choose the path with the best tick
metric (lower is better). Defaults: 1 for LANs; 6 for
WANs
If more than one path has the same tick count, then
Novell RIP will choose the one with the least hops.
If hop count is also equal, Novell RIP implements
load sharing if it has been configured.
Load Sharing



To configure a Cisco router to load share
across equal paths, you must use the ipx
maximum-paths paths command.
paths can be a value from 1 to 512. The
default is 1. That’s why you must configure
the router to load share.
IPX load shares on a packet-by-packet basis in
round-robin fashion.


The first packet is sent along the first path, the second
packet along the second path, and so on.
When the final path is reached, the next packet is sent to
the first path, the next to the second path, and so on.
Service Advertising Protocol

SAP is used by network devices, such as
servers and printers, to advertise their
service to clients and build SAP tables.




SAP updates are sent every 60 seconds
Routers attached to Novell segments listen to
all SAPs and also build SAP tables.
If a client requests service (GNS) and a
server does not exist on the same segment,
then the router will respond with a server
address from its SAP table.
The client can then send packets directly to
the server.
Get Nearest Server


GNS packets are broadcasted as a client is
attempting to login. The GNS locates the
nearest server.
If there is a NetWare server on the same LAN
as the client, it will respond to the GNS
request. Otherwise, the router will respond.
Configuration Overview

Global Configuration Tasks:



Enable Novell RIP with the ipx routing [node]
command. If no node is specified, the router uses
the MAC of the interface. Node must be specified if
there are only serial interfaces.
Define the number of paths to load share using the
ipx maximum-paths paths command if multiple
paths exist to a destination.
Interface Configuration Tasks:


Define the network using the ipx network network
command.
Define the Novell encapsulation used on Ethernet
interfaces with the ipx encapsulation cisconame command.
Things to Remember

You can configure multiple networks on the
same interface. In order to do so, you
must...




Use subinterfaces (e.g. e0.1, e0.2, e0.3, etc.)
Use different network numbers on each
subinterface.
If you have multiple paths to the same
destination, be sure to use the ipx maximumpaths command to provide load sharing.
Take advantage of the e-Lab activities for this
chapter--especially 7.4.2 and 7.4.3. You can
follow this link to Del Mar’s site.
Monitoring & Managing IPX Networks
Do the e-Labs to practice these commands!!
Command
Displays
Monitoring Commands
show ipx interface
IPX status and parameters
show ipx route
Routing table
show ipx servers
IPX server list
show ipx traffic
Number & type of packets
Troubleshooting Commands
debug ipx routing activity
Info about RIP updates
debug ipx sap
Info about SAP upsdates
ping
testing connectivity